1. Field of Invention
The present invention relates to an electrooptical substrate device for an electrooptical apparatus, such as a liquid-crystal apparatus, of a so-called TFT active-matrix drive scheme for active-matrix-driving pixel electrodes by thin film transistors (hereinafter xe2x80x9cTFTsxe2x80x9d). The invention also relates to a manufacturing method for the same, an electrooptical apparatus including such an electrooptical substrate device, an electronic apparatus having such an electrooptical apparatus, and a manufacturing method for a substrate device.
2. Description of Related Art
In this type of an electrooptical substrate device, pixel-electrode-switching TFTs are respectively provided on a plurality of pixel electrodes that are arranged in a matrix form. Each TFT is turned on each time a scanning signal is applied to the gate electrode thereof, to write an image signal onto the pixel electrode through the TFT.
Particularly, N-channel TFTs, having as carriers high-mobility electrons, are used to enable control by the TFTs having a high-performance transistor characteristic when effecting pixel-switching control. Recently, as the drive frequency of an electrooptical apparatus increases, the N-channel TFTs having high-mobility electrons as carriers are still being used in order to cope with the higher driving frequency.
On the other hand, in order to perform a higher level of driving, such as high-frequency driving, there is a need to further enhance the performance of such a pixel-switching TFT. For this reason, it is proposed to apply the SOI (Silicon On Insulator) structure, or SOI art, in the semiconductor manufacturing technology to an electrooptical substrate device of that kind. Specifically, a single-crystal semiconductor layer is formed by bonding or the like on an insulating layer of quartz or sapphire formed on a substrate, to fabricate transistors on the single-crystal semiconductor layer. The application of such an SOI art makes it possible to fabricate single-crystal silicon TFTs that are higher in performance than the amorphous-silicon or polysilicon TFTs on an electrooptical substrate device.
However, where an SOI structure is adopted, the N-channel MOS TFT has a tendency to build up holes as surplus carriers in the channel region during the operation thereof. According to the research by the present inventor, this is due to a parasitic bipolar phenomenon resulting from a substrate float effect, because in the SOI structure, an insulator layer is arranged below the channel region. In this phenomenon, in the case of the N-channel MOS TFT, the electrons, of among the electron-hole pairs caused due to impact ionization within a drain depletion layer, directly flow into the drain. However, the holes are built up, as surplus carriers, in the vicinity of the source beneath the channel, to raise the channel potential and further promote impact ionization. As a result, the accumulation amount of surplus holes increases to increase the drain current in an avalanche-effect fashion.
Accordingly, in the n-channel MOS TFT adopting an SOI structure, a need exists to provide a body contact to remove such surplus carriers. More specifically, a portion of a semiconductor layer needs to be extended from the channel region in order to remove surplus carriers, and to place a surplus-carrier-removing conductor layer in contact with that extended portion. This causes a problem of complication in the overlying structure on a substrate and in the manufacturing process. Furthermore, such a body contact makes it difficult to fabricate TFTs within a limited region of non-opening area in each pixel not contributing to actual display in the image display region. There is also a problem of interference with the broadening of the opening area of each pixel.
The present invention addresses the foregoing problem, and provides each pixel with comparatively high performance transistors suited to broaden the opening area in each pixel, and provides an electrooptical substrate device enabling bright, high-quality image display, a manufacturing method for the same, an electrooptical apparatus including such an electrooptical substrate device, an electronic apparatus having such an electrooptical apparatus, and a manufacturing method for a substrate device to be suitably used in such an electrooptical apparatus.
An electrooptical substrate device of the invention that addresses the foregoing problem includes: on a substrate, an insulator layer; and an N-type single-crystal semiconductor layer formed on the insulator layer, and including a P-type source region, a P-type drain region and a channel region; a gate electrode formed on the single-crystal semiconductor layer in the channel region through a gate insulating film; a scanning line connected to the gate electrode; a data line connected to one of the source region and the drain region; and a pixel electrode connected to the other of the source region and the drain region. A P-channel transistor is architected by the single-crystal semiconductor layer, the gate insulating film and the gate electrode to switch-control the pixel electrode.
The use of the electrooptical substrate device of the invention makes it possible to architect an electrooptical apparatus that is capable of being active-matrix-driven by switch-controlling the pixel electrodes due to the transistors connected to the scanning and data lines. In the electrooptical substrate device of the invention, particularly an N-type single-crystal semiconductor layer is formed on an insulator layer, to architect P-channel transistors on a so-called SOI substrate. The P-channel transistor, having holes as carriers, is generally inferior in transistor performance to the N-channel transistor correspondingly to its low mobility. However, because of being formed on an SOI substrate, it is made to be not inferior in its transistor performance to the MOS transistor configured using, for example, polysilicon or amorphous silicon as a semiconductor layer. Namely, the P-channel transistor on the SOI substrate provides sufficiently high transistor performance to switch-control the pixel electrode. Conversely, despite being formed on the SOI substrate, because it is of the P-channel type, the parasitic bipolar effect due to a substrate float effect as noted before is practically not a problem, which is different from the case with the N-channel type. This is considered to be because the P-channel transistor is low in the impact ionization ratio of holes. For this reason, there is no need for the P-channel transistor to perform the removal of surplus carriers required in practical use in the N-channel transistor as noted before. Consequently, a structure does not need to be fabricated to remove such surplus carriers in each pixel, correspondingly enabling an increase in the opening ratio in each pixel. At the same time, there is no complication incurred in the overlying structure of each pixel and in the manufacturing process. This ultimately results in realizing an electrooptical substrate device that is capable of being switch-controlled or active-matrix-driven by the transistors having comparatively high performance to display a bright, high-quality image.
In one form of an electrooptical substrate device of the invention, the transistor is a P-channel MOS (Metal Oxide Silicon) transistor.
In this form, because the P-channel MOS transistor is provided on the substrate, a conductor layer does not have to be provided to remove the carriers built up in the semiconductor layer during operation, which is different from the N-channel MOS transistor. Because the P-channel transistor is a transistor made up on the SOI substrate, sufficiently high transistor performance is obtained in switch-controlling the pixel electrode.
Another form of an electrooptical substrate device of the invention further includes an interlayer insulating film formed on the gate electrode, a source electrode formed by a P-type conductor layer on the interlayer insulating film and connected to the source region, and a drain electrode formed by a P-type conductor layer on the interlayer insulating film and connected to the drain region. The data line is connected to one of the source region and the drain region by way of one of the source electrode and the drain electrode, the pixel electrode being connected to the other of the source region and the drain region by way of the other of the source electrode and the drain electrode.
In accordance with this form, because the P-type source region is connected with a source electrode formed by a P-type conductor layer, a favorable electrical connection is obtained between the two. If a source electrode formed by an N-type conductor layer is connected, a PN junction is formed between the two, and hence favorable electrical connection is not to be expected. On the other hand, because the P-type drain region is connected with a drain electrode formed by a P-type conductor layer, favorable electrical connection is obtained between the two.
In this form, the P-type conductor layer may be doped to a P-type by ion implantation after depositing a conductor layer.
In accordance with this structure, electrical connection can be favorably provided between the conductor layer doped in P-type by ion implantation and the P-type source or drain region.
Otherwise, in this form, the source electrode may be connected to the source region through a contact hole opened in the interlayer insulating film, the drain electrode being connected to the drain region through a contact hole opened in the interlayer insulating film.
In accordance with this structure, electrical connection can be favorably provided between the source electrode formed by the P-type conductor layer and the P-type source region through the contact hole, while electrical connection is favorably provided between the drain electrode formed by the P-type conductor layer and the P-type drain region through the contact hole.
Another form of an electrooptical substrate device of the invention further includes a lower shadow film covering the channel region at an under side thereof, the insulator layer being formed on the lower shadow film.
In accordance with this form, the channel region is covered at an under side by the lower shadow film. Consequently, the channel region can be shadowed from the reflection light upon a back surface of the substrate, or from the return light, such as the light shining from another light bulb of a plural-plate-type projector using a plurality of light bulbs, including the electrooptical substrate devices, and streaming through a combination optical system. As a result, it is possible to effectively reduce or prevent occurrence of light leak current due to a photoelectric effect resulting from return light in the channel region.
In another form of an electrooptical substrate device of the invention, a CMP process is performed on a surface of the insulator layer at a side facing the single-crystal semiconductor layer.
In accordance with this form, because a CMP process is performed over the surface of the insulator layer, the single-crystal semiconductor layer can be bonded onto the surface of the insulator layer. Particularly, in the case of forming a lower shadow film, such an SOI structure is obtained without problem by thus performing a CMP process on the insulator layer.
In another form of an electrooptical substrate device of the invention, the substrate is formed of quartz glass.
In accordance with this form, an SOI structure is obtained that is architected with a P-channel transistor on the quartz glass.
In another form of an electrooptical substrate device of the invention, the substrate is formed of glass.
In accordance with this form, an SOI structure is architected with P-channel transistors on the glass.
In another form of an electrooptical substrate device of the invention, the pixel electrode is formed by a transparent electrode.
In accordance with this form, the electrooptical substrate device is used to realize a transmission-type electrooptical apparatus that light transmits through a transparent electrode, or a reflection-type electrooptical apparatus that light reflects through a transparent electrode.
In another form of an electrooptical substrate device of the invention, the pixel electrode is formed by a reflecting electrode.
According to this form, the electrooptical substrate device is used to realize a reflection-type electrooptical apparatus that light reflects upon a reflecting electrode.
Another form of an electrooptical substrate device of the invention further includes a peripheral circuit, on the substrate, in a periphery of an image display region, in which the pixel electrode is formed. The peripheral circuit includes an N-channel transistor, the N-channel transistor having a conductor layer to suck out carriers built up in the semiconductor layer thereof. The P-channel transistor provided in the image display region does not have a conductor layer to suck out carriers built up in the semiconductor layer thereof.
In accordance with this form, the peripheral circuits, such as the scanning-line drive circuit and the data-line drive circuit, are configured at least in part with high-performance N-channel transistors. Particularly, the peripheral region has enough area to fabricate circuits in an amount corresponding to the lack of need to secure an opening area, as compared to the image display region where a pixel opening area needs to be secured. Accordingly, the problem is comparatively small if the N-channel transistor, constituting a peripheral circuit, is provided with a conductor layer to suck out the built-up surplus carriers. Conversely, the use of a peripheral circuit, including a high-performance N-channel transistor provided with a conductor layer to suck out such surplus carriers, enables a high level of driving or control. On the other hand, the P-channel transistor in the image display region, not requiring the provision of a conductor layer to suck out built-up surplus carriers, can have a broadened opening area in each pixel. These structures ultimately result in the capability of image display with brightness and high quality.
Another form of an electrooptical substrate device of the invention further includes, on the substrate, an intermediate conductor layer interlevel-connecting the other of the source region and the drain region and the pixel electrode, and including a pixel-potential capacitance electrode, and a capacitance line including a fixed-potential capacitance electrode arranged oppositely to the pixel-potential capacitance electrode through a dielectric film. A storage capacitance is architected by the pixel-potential capacitance electrode and the fixed-potential capacitance electrode, and connected to the pixel electrode. At least one of the capacitance line and the intermediate conductor layer is formed by a conductive shadow film and includes a portion covering the channel region on the substrate from above.
In accordance with this form, interlevel connection is provided between the pixel electrode and the other of the source and drain regions by an intermediate conductor layer. Consequently, even if the interlayer distance is long between the two, the two can be favorably electrically connected, while avoiding the technical difficulty in connecting the two through a long-distance contact hole or the like. Furthermore, the intermediate conductor layer, having a function of such interlevel connection, also serves as a pixel-potential capacitance electrode of a storage capacitance. Consequently, the overlying structure and the manufacturing process can be simplified as compared to the case of separately forming the interlevel-connecting conductor layer and the conductor layer for the pixel-potential capacitance electrode. In addition, because at least one of the intermediate conductor layer and the capacitance line, both of which architecting a storage capacitance, is formed by a conductive shadow film covering the channel region from above, the channel region can be shadowed against the incident light from above. This can effectively reduce or prevent occurrence of light leak current due to a photoelectric effect resulting from the incident light in the channel region. Moreover, the overlying structure and the manufacturing process can be simplified as compared to the case of separately forming such a shadow film.
Incidentally, an island-formed interlevel-connecting conductor layer, of the same film as the intermediate conductor layer, may be provided between the data line and one of the source and drain regions. Meanwhile, in this form, a lower shadow film noted above, if provided, can shadow the channel region at its upper and lower sides, thus providing a further advantage.
In this form, the storage capacitance is provided at least in a part of a region overlapped with the scanning line as viewed in plan.
In accordance with this structure, because a storage capacitance can be fabricated, even in a region overlapped with the scanning line, storage capacitance can be increased without narrowing the opening area in each pixel.
Otherwise, in this form, the storage capacitance may be provided at least in a part of a region overlapped with the data line as viewed in plan.
In accordance with this structure, because a storage capacitance can be fabricated, even in a region overlapped with the data line, storage capacitance can be increased without narrowing the opening area in each pixel.
An electrooptical apparatus of the invention that addresses the foregoing problem includes various forms of the electrooptical substrate device as described above; a counter substrate arranged opposite to the electrooptical substrate device; and an electrooptical substance sandwiched between the counter substrate and the electrooptical substrate device.
Because the electrooptical apparatus is structured having the foregoing electrooptical substrate device, it can display a bright, high-quality image.
An electronic apparatus of the invention that addresses the foregoing problem includes an electrooptical apparatus as described above.
Because the electronic apparatus of the invention has the above electrooptical apparatus, various kinds of electronic apparatus are realized that are capable of displaying a bright, high-quality image, e.g., a projector, a display apparatus built in an OA appliance, and a display apparatus of a cellular phone.
A method for manufacturing an electrooptical substrate device of the invention that addresses the foregoing problem manufactures a form having a contact hole in the foregoing electrooptical substrate device of the invention, and includes: a first depositing step for forming the interlayer insulating film on the single-crystal semiconductor layer; an opening step for opening the contact hole in the interlayer insulating film; a second depositing step for forming a material film of a predetermined kind to be formed into the P-type conductor layer, on the interlayer insulating film in which the contact hole is opened; and an ion-implant step for implanting ions to the formed material film to thereby form the P-type conductor. In the ion-implant step, ions are implanted with an inclination by a predetermined angle X with respect to a centerline of the contact hole, such that ions are implanted to a region of the material film formed on a side surface of the contact hole, and the predetermined angle X is set within a range to implant ions to a region of the material film formed on a bottom surface of the contact hole.
In accordance with the method for manufacturing an electrooptical substrate device of the invention, while forming a P-type conductor layer that forms a source electrode or drain electrode on the interlayer insulating film in which a contact hole is opened, a material film of a predetermined kind of, e.g., polysilicon, to be formed into a P-type conductor layer, is first formed by a CVD (chemical vapor deposition) process or the like. Thereafter, ions, e.g., B (boron), are implanted to the formed material film, thereby forming a P-type conductor layer.
Particularly the contact hole at its side surface is sharply vertical over the substrate. Consequently, even if ions are implanted along a centerline of the contact hole, i.e., along the side surface of the contact hole in the ion implant process, it is for practical purposes almost or entirely impossible to implant ions to a material film region formed on the side surface. Nevertheless, if ions are implanted in a direction that is greatly inclined from the centerline of the contact hole, it will be, for practical purposes, almost or entirely impossible to implant ions to a material film region formed on a bottom surface in the contact hole. This is because the contact hole at its edge and peripheral portion prevents an ion path directed with inclination toward the bottom surface of the contact hole. In any case, it is difficult or impossible to reduce, without unevenness, the resistance of the material film at the inside of the contact hole. This makes it difficult to realize a favorable electrical connection by a P-type conductor layer between the pixel electrode or data line and the source or drain region.
In contrast, the invention implants ions with inclination at a predetermined angle X with respect to the contact-hole centerline in the ion implant process, and ions are implanted to the material film region formed on the side surface of the contact hole. At the same time, because the predetermined angle X is set within a range to implant ions to the material film region formed on the bottom surface of the contact hole, ions can also be implanted to the material film region that is formed on the bottom surface of the contact hole. Consequently, the material film inside the contact hole can be comparatively easily reduced in resistance. It is possible to realize a favorable electrical connection by a P-type conductor layer between the pixel electrode or data line and the source or drain region. This can ultimately enhance the quality in the display image.
As described above, the form having a contact hole in the foregoing electrooptical substrate device of the invention can be comparatively easily manufactured by the use of an ion implant process.
In one form of a method for manufacturing an electrooptical substrate device of the invention, in the ion implant step, ions are implanted in a plurality of directions at a different timing or simultaneously with an inclination by a predetermined angle X with respect to a centerline of the contact hole. The predetermined angle X is set, in each of the plurality of directions, within a range to implant ions to the region of the material film positioned at a center of the bottom surface of the contact hole.
In accordance with this form, ions are implanted with inclination in four directions at a different timing or simultaneously in the ion implant process. Concerning each region in the bottom surface of the contact hole, particularly the ion path directed to a different region depending on an inclination direction is hindered by the edge and peripheral portion of the contact hole, and the ion path directed to a different region depending on an inclination direction is not hindered by the edge and peripheral portion of the contact hole. Moreover, also concerning each region in the side surface of the contact hole, the ion path directed to a different region depending on an inclination direction is hindered by the edge and peripheral portion of the contact hole, and the ion path directed to a different region depending on an inclination direction is not hindered by the edge and peripheral portion of the contact hole. Accordingly, by changing the inclination direction of ion implantation, the region to which ions are to be implanted can be changed for each region of the bottom surface of the contact hole. For this reason, by properly changing the inclination direction, e.g., in three directions, in four directions, in eight directions, or in every direction surrounding the center of the contact hole, the region in the bottom surface of the contact hole to which ions are to be implanted can be all or almost all of the region of the bottom surface. At the same time, also concerning the side surface of the contact hole, the region to which ions are to be implanted can be all or almost all the region thereof. Consequently, the material film inside of the contact hole can be comparatively easily reduced in resistance. It is possible to realize a favorable electrical connection by a P-type conductor layer between the pixel electrode or data line and the source or drain region.
In one form of a method for manufacturing an electrooptical substrate device of the invention, in the opening step, the contact hole is opened in a pillar form. The predetermined angle X in the ion implant step is set to satisfy 0 less than Xxe2x89xa6tanxe2x88x921{(axe2x88x922c)/2e}, where a diameter of the contact hole is xe2x80x9caxe2x80x9d, a depth of the contact hole is xe2x80x9cexe2x80x9d, and a film thickness of the material film is xe2x80x9ccxe2x80x9d.
In this form, the contact hole is opened in a pillar form, e.g., in a circular or angular form. Accordingly, the material film region that is formed on the side surface of the same is sharply vertical. Nevertheless, because the predetermined angle X in the ion implant process is set such that 0 less than X, ions can be implanted to the material film region formed on the side surface of the contact hole. Moreover, because the predetermined angle X is set to satisfy Xxe2x89xa6tanxe2x88x921{(axe2x88x922c)/2e}, ions can also be implanted to the bottom surface center of the contact hole. Accordingly, by providing ion implantation, e.g., in a plurality of directions, such as in four directions at a different timing or simultaneously, ions can be implanted to all or almost all of the region of the bottom and side surfaces of the contact hole.
In another form of a method for manufacturing an electrooptical substrate device of the invention, in the opening step, the contact hole is opened in a circular or pyramidal cone form, broadening in a direction from the interlayer insulating film toward the conductor layer. The predetermined angle X in the ion implant step is set to satisfy 0xe2x89xa6Xxe2x89xa6tanxe2x88x921{(dxe2x88x92a)/2e}, where the diameter at the bottom surface is xe2x80x9caxe2x80x9d, a diameter at an opening edge of the contact hole is xe2x80x9cdxe2x80x9d, a depth of the contact hole is xe2x80x9cexe2x80x9d, and a film thickness of the material film is xe2x80x9ccxe2x80x9d.
In this form, the contact hole is opened in a circular or pyramidal cone form, broadening in a direction toward the conductor layer, i.e., opened in the upper direction over the substrate. Accordingly, the material film region that is formed on the side surface of the same is vertical in an inclined fashion. Nevertheless, because the predetermined angle X in the ion implant process is set such that 0xe2x89xa6X, ions can be implanted to the material film region formed on the side surface of the contact hole. Particularly, because there is a slant in the side surface of the contact hole, even if X=0, ions can be implanted to the material film region that is formed on the side surface of the contact hole depending upon the degree thereof. Moreover, because the predetermined angle is set to satisfy Xxe2x89xa6tanxe2x88x921{(dxe2x88x92a)/2e}, ions can also be implanted to the bottom surface center of the contact hole. Accordingly, by providing ion implantation, e.g., in a plurality of directions, such as four directions in different timing or simultaneously as noted above, ions can be implanted to all or almost all of the region of the bottom and side surfaces of the contact hole.
Otherwise, in another form of a method for manufacturing an electrooptical substrate device of the invention, in the opening step, the contact hole is opened, and has a first contact hole portion opened in a circular or pyramidal cone form, broadening in a direction from the interlayer insulating film toward the conductor layer, and a second contact hole portion opened in a pillar form continuing from the bottom of the first portion. The predetermined angle X in the ion implant step is set to satisfy 0 less than Xxe2x89xa6(axe2x88x922c)/2(csin Y+bxe2x88x92c}, where Y=tanxe2x88x921{(dxe2x88x92a)/2e}, where a diameter of the second contact hole portion is xe2x80x9caxe2x80x9d, a diameter at an opening edge of the first contact hole portion is xe2x80x9cdxe2x80x9d, a depth of the first contact hole portion is xe2x80x9cexe2x80x9d, a depth of the second contact hole portion is xe2x80x9cbxe2x80x9d, and a film thickness of the material film is xe2x80x9ccxe2x80x9d.
In this form, the contact hole has a first hole portion that is opened in a circular or pyramidal cone form, broadening in a direction of toward the conductor layer, and a second hole portion opened in a pillar-form continuing from a bottom of the first portion. On the substrate, the contact hole has a pillar-like contact hole, as noted above, opened as a second contact hole portion, and a circular or pyramidal cone formed contact hole, as noted above, is opened as a first contact hole portion continuing to the above from the contact hole (toward an opening of the contact hole). Accordingly, the material film region that is formed on the side surface of the first contact hole portion is slanted. Furthermore, the material film region that is formed on the side surface of the second contact hole portion is nearly sharply vertical. Nevertheless, because the predetermined angle X in the ion implant process is set such that 0 less than X, ions can be implanted to the material film region formed on the side surface of the first and second contact hole portions. Moreover, because the predetermined angle X is set to satisfy Xxe2x89xa6(axe2x88x922c)/2(csin Y+bxe2x88x92c) where Y=tanxe2x88x921{(dxe2x88x92a)/2e}, ions can also be implanted to the bottom surface center of the second contact hole portion. Accordingly, by providing ion implantation, e.g., in a plurality of directions, such as in four directions at a different timing or simultaneously as noted before, ions can be implanted to all or almost all of the region of the bottom and side surfaces of the contact hole.
A method for manufacturing a substrate device of the invention that addresses the foregoing problem manufactures a substrate device having, on a substrate, an interlayer insulating film in which a hole is opened, and a conductor layer formed on the interlayer insulating film and provided in the hole, structuring at least a part of an electronic element or electronic circuit by the conductor layer on the substrate. The method includes a step of opening the hole in the interlayer insulating film; a step of forming a material film of a predetermined type to be formed into the conductor layer, on the interlayer insulating film in which a hole is opened; and an ion implant step for implanting ions to the formed material film to thereby form the conductor layer. In the ion implant step, ions are implanted with an inclination by a predetermined angle X with respect to a centerline of the hole, such that ions are implanted to a region of the material film that is formed on a side surface of the hole, and the predetermined angle X is set within a range to implant ions to a region of the material film that is formed on a bottom surface of the hole.
In accordance with the method for manufacturing a substrate device of the invention, where forming a conductor layer to be formed into at least a part of an electronic element or electronic circuit on the interlayer insulating film on which a hole is formed, a material film of a predetermined type to be formed into a conductor layer of, e.g., polysilicon, is first formed by a CVD (chemical vapor deposition) process or the like. Thereafter, ions, e.g., B (boron), are implanted to the formed material film, thereby forming a conductor layer.
Particularly, the hole at its side surface is sharply vertical over the substrate. Consequently, if ions are implanted along a centerline of the hole, i.e., along the side surface of the hole in the ion implant process, it is for practical purposes almost or entirely impossible to implant ions to a material film region formed on the side surface. Nevertheless, if ions are implanted in a direction that is greatly inclined from the centerline of the hole, it will be, for practical purposes, almost or entirely impossible to implant ions to a material film region that is formed on a bottom surface in the hole. This is because the hole at its edge and peripheral portion prevents an ion path directed with inclination toward the bottom surface of the hole. In any case, it is difficult or impossible to reduce, without unevenness, the resistance of the material film inside the hole. This makes it difficult to architect a favorable electronic element or electronic circuit by a conductor layer.
In contrast, the invention implants ions with inclination at a predetermined angle X with respect to the contact-hole centerline in the ion implant process, and ions are implanted to the material film region formed on the side surface of the hole. At the same time, because the predetermined angle X is set within a range to implant ions to the material film region that is formed on the bottom surface of the hole, ions can also be implanted to the material film region that is formed on the bottom surface of the hole. Consequently, the material film that is inside the hole can be comparatively easily reduced in resistance. It is possible to architect a favorable electronic element or electronic circuit by a conductor layer.
In one form of a method for manufacturing a substrate device of the invention, the substrate device further includes, on the substrate, another conductor layer that is connected to the conductor layer through the hole. The method further includes a step for forming the interlayer insulating film on the other conductor layer.
In accordance with this form, the hole serving as a contact hole is used to architect, on the substrate, an electronic element or electronic circuit including two conductor layers that are insulated by the interlayer insulating film.
In another form of a method for manufacturing a substrate device of the invention, in the step of opening a hole, the hole is formed in a cavity or recess form, not penetrating through the interlayer insulating film.
In accordance with this form, the hole is not in penetration, and not used as a contact hole. Nevertheless, there are cases of manufacturing substrate devices for electronic elements or circuits necessarily or preferably having a conductor layer formed on the surface of an interlayer insulating film where irregularities exist, depending on the various types of requests and apparatus specifications. In such a case, the foregoing effect of the invention is exhibited to a corresponding extent.
In another form of a method for manufacturing a substrate device of the invention, in the ion implant step, ions are implanted in a plurality of directions at a different timing or simultaneously with an inclination by a predetermined angle X with respect to a centerline of the hole. The predetermined angle X is set, in each of the plurality of directions, within a range to implant ions to a region of the material film positioned at a center of a bottom surface of the hole.
In accordance with this form, ions are implanted with inclination in four directions at a different timing or simultaneously in the ion implant process. Concerning each region in the bottom surface of the hole, particularly the ion path directed toward a different region, depending on an inclination direction, is hindered by the edge and peripheral portion of the hole, and the ion path directed toward a different region depending on an inclination direction is not hindered by the edge and peripheral portion of the hole. Moreover, also concerning also each region in the side surface of the hole, the ion path directed toward a different region, depending on an inclination direction, is hindered by the edge and peripheral portion of the hole, and the ion path directed toward a different region depending on an inclination direction is not hindered by the edge and peripheral portion of the hole. Accordingly, by changing the inclination direction of ion implantation, the region to which ions are to be implanted can be changed for each region in the bottom surface of the hole. For this reason, by properly changing the inclination direction, e.g., in three directions, in four directions, in eight directions, or in every direction surrounding the center of the hole, the region in the bottom surface of the hole to which ions are to be implanted can be all or almost all of the region of the bottom surface. At the same time, concerning the side surface of the hole, the region to which ions are to be implanted can be all or almost all the region thereof. Consequently, the material film that is inside the hole can be comparatively easily reduced in resistance.
In one form of a method for manufacturing a substrate device of the invention, in the step of opening a hole, the hole is opened in a pillar form. The predetermined angle X in the ion implant step is set to satisfy 0 less than Xxe2x89xa6tanxe2x88x921{(axe2x88x922c)/2e}, where a diameter of the hole is xe2x80x9caxe2x80x9d, a depth of the hole is xe2x80x9cexe2x80x9d, and a film thickness of the material film is xe2x80x9ccxe2x80x9d.
In this form, the hole is opened in a pillar form, e.g., in a circular or angular form. Accordingly, the material film region that is formed on the side surface of the same is sharply vertical. Nevertheless, because the predetermined angle X in the ion implant process is set such that 0 less than X, ions can be implanted to the material film region that is formed on the side surface of the hole. Moreover, because the predetermined angle X is set to satisfy Xxe2x89xa6tanxe2x88x921{(axe2x88x922c)/2e}, ions can also be implanted to the bottom surface center of the hole. Accordingly, by providing ion implantation, e.g., in a plurality of directions, such as in four directions at a different timing or simultaneously, ions can be implanted to all or almost all of the region of the bottom and side surfaces of the hole.
In another form of a method for manufacturing a substrate device of the invention, in the step of opening a hole, the hole is opened in a circular or pyramidal cone form, broadening in a direction from the interlayer insulating film toward the conductor layer. The predetermined angle X in the ion implant step is set to satisfy 0xe2x89xa6Xxe2x89xa6tanxe2x88x921{(dxe2x88x92a)/2e}, where a diameter at a bottom surface of the hole is xe2x80x9caxe2x80x9d, a diameter at an opening edge of the hole is xe2x80x9cdxe2x80x9d, a depth of the hole is xe2x80x9cexe2x80x9d, and a film thickness of the material film is xe2x80x9ccxe2x80x9d.
In this form, the hole is opened in a circular or pyramidal cone form, broadening in a direction of toward the conductor layer, i.e., opened toward the above over the substrate. Accordingly, the material film region that is formed on the side surface of the same is slanted. Nevertheless, because the predetermined angle X in the ion implant process is set such that 0xe2x89xa6X, ions can be implanted to the material film region that is formed on the side surface of the hole. Because there is a slant in the side surface of the hole, even if X=0, ions can be implanted to the material film region that is formed on the side surface of the hole depending upon the degree thereof. Moreover, because the predetermined angle is set to satisfy Xxe2x89xa6tanxe2x88x921{(dxe2x88x92a)/2e}, ions can also be implanted to the bottom surface center in the hole. Accordingly, by providing ion implantation, e.g., in a plurality of directions, such as in four directions at a different timing or simultaneously as noted above, ions can be implanted to all or almost all of the region of the bottom and side surfaces of the hole.
In another form of a method for manufacturing a substrate device of the invention, in the step of opening a hole, the hole is opened including a first hole portion in a circular or pyramidal cone form, broadening in a direction from the interlayer insulating film toward the conductor layer, and a second hole portion opened in a pillar form continuing from a bottom of the first portion. The predetermined angle X in the ion implant step is set to satisfy 0 less than Xxe2x89xa6(axe2x88x922c)/2(csin Y+bxe2x88x92c}, where Y=tanxe2x88x921{(dxe2x88x92a)/2e}, where a diameter of the second hole portion is xe2x80x9caxe2x80x9d, a diameter at an opening edge of the first hole portion is xe2x80x9cdxe2x80x9d, a depth of the first hole portion is xe2x80x9cexe2x80x9d, a depth of the second hole portion is xe2x80x9cbxe2x80x9d, and a film thickness of the material film is xe2x80x9ccxe2x80x9d.
In this form, the hole has a first hole portion that is opened in a circular or pyramidal cone form, broadening in a direction toward the conductor layer, and a second hole portion that is opened in a pillar form continuing from a bottom of the first portion. On the substrate, at the floor of the hole, a pillar-like hole, as noted above, is opened as a second hole portion, and a circular or pyramidal cone formed hole, as noted above, is opened as a first hole portion continuing to the upper side from the second hole (opening of the hole). Accordingly, the material film region that is formed on the side surface of the first hole portion is slanted. Furthermore, the material film region formed on the side surface of the second hole portion is nearly sharply vertical. Consequently, because the predetermined angle X in the ion implant process is set such that 0 less than X, ions can be implanted to the material film region that is formed on the side surface of the first and second hole portions. Moreover, because the predetermined angle X is set to satisfy Xxe2x89xa6(axe2x88x922c)/2(csin Y+bxe2x88x92c}, where Y=tanxe2x88x921{(dxe2x88x92a)/2e}, ions can be implanted also to the bottom surface center of the second hole portion. Accordingly, by providing ion implantation, e.g., in a plurality of directions, such as in four directions at a different timing or simultaneously, as noted above, ions can be implanted to all or almost all of the region of the bottom and side surfaces of the hole.
In another form of a method for manufacturing a substrate device of the invention, in the ion implant step, ions are implanted to make the material film, including polysilicon, into the conductor layer of P-type doped polysilicon.
In accordance with this form, it is possible to architect a preferred electronic element or circuit by a conductor layer of P-type doped polysilicon.
The operation and other advantages of the invention will be made more apparent from the embodiment to be explained in the following.